title: Investigation of folic acid stability in fortified instant noodles by use of capillary electrophoresis and reversed-phase high performance liquid chromatography.
abstract: A single enzyme treatment with alpha-amylase, prior to the quantification of added folic acid (FA) in fortified instant fried Asian noodles with analysis performed by capillary zone electrophoresis (CZE) and reversed-phase high performance liquid chromatography (RP-HPLC) with UV detection, is described. The method was validated and optimized for capillary electrophoresis (CE) with separation achieved using a 8 mM phosphate-12 mM borate run buffer with 5% MeOH at pH 9.5. FA was well separated from matrix components with nicotinic acid (NA) employed as an internal standard. In a comparative study, separation of FA was performed using HPLC with a mobile phase consisting of 27% MeOH (v/v) in aqueous potassium phosphate buffer (3.5 mM KH(2)PO(4) and 3.2 mM K(2)HPO(4)), pH 8.5, and containing 5 mM tetrabutylammonium dihydrogen phosphate as an ion-pairing agent. For both methods, excellent results were obtained for various analytical parameters including linearity, accuracy and precision. The limit of detection was calculated to be 2.2 mg/L for CE without sample stacking and 0.10 mg/L with high performance liquid chromatography (HPLC). Sample extraction involved homogenization and enzymatic extraction with alpha-amylase. Results indicated that FA was stable during four main stages of instant fried noodle manufacturing (dough crumbs, cut sheets, steaming and frying).
authors.affiliation: Applied Chemistry, School of Applied Sciences, RMIT University, GPO Box 2476V, Melbourne 3001, Victoria, Australia.
authors.forename: Rodney
authors.initials: R
authors.lastname: Hau Fung Cheung
authors.forename: Paul D
authors.initials: PD
authors.lastname: Morrison
authors.forename: Darryl M
authors.initials: DM
authors.lastname: Small
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Marriott
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004355:Drug Stability; D019075:Electrophoresis, Capillary / Q000379:methods*; D005492:Folic Acid / Q000032:analysis* / Q000378:metabolism; D005504:Food Analysis / Q000379:methods*; D005527:Food, Fortified / Q000032:analysis*; D005525:Food-Processing Industry; D009525:Niacin; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000516:alpha-Amylases / Q000378:metabolism
chemical_list: D009525:Niacin; D005492:Folic Acid; D000516:alpha-Amylases